Methods and apparatus for sealing an opening of a processing chamber

ABSTRACT

In one embodiment, a slit valve is provided that is adapted to seal an opening and that includes a valve housing having a first wall, a first opening formed in the first wall, a second wall and a second opening formed in the second wall. The slit valve also includes a closure member having a sealing portion adapted to contact the second wall and seal the second opening, and a bracing member moveable relative to the sealing portion and adapted to contact the first wall. The slit valve further includes at least one actuating mechanism adapted to (1) move the sealing portion toward the second wall and into contact with the second wall; and (2) move the bracing member away from the sealing portion and into contact with the first wall so as to brace the sealing portion against the second wall. Numerous other aspects are provided.

This application is a continuation of and claims priority from U.S.patent application Ser. No. 10/844,974 filed May 12, 2004 which claimspriority from U.S. Provisional Patent Application Ser. No. 60/470,140,filed May 13, 2003, each of which is hereby incorporated by referenceherein in its entirety.

FIELD OF THE INVENTION

The present invention relates generally to semiconductor devicemanufacturing and more particularly to methods and apparatus for sealingan opening of a processing chamber.

BACKGROUND OF THE INVENTION

A substrate processing chamber typically communicates with a substratetransfer chamber through a sealable opening that is both wide andrelatively short to accommodate insertion and removal ofhorizontally-oriented substrates. It is known to use a slit valve toseal such an opening. For example, a sealing plate of the slit valve maybe extended to seal the opening, and retracted to permit passage ofsubstrates through the opening. Slit valve designs that avoid theproblems of (1) particle generation through rubbing friction, and (2)uneven compression of resilient sealing elements, are preferred.

During certain types of substrate processing steps, a pressuredifferential may exist between the processing chamber and the transferchamber such that high pressure within the processing chamber pushesoutward against the sealing plate of the slit valve. The slit valvethereby is subjected to stresses and fatigue, the amounts of whichincrease with the pressure differential. Pressure differential effectsare exacerbated when large substrates, such as those employed for flatpanel displays, are involved (e.g., as a larger substrate requires alarger opening between the processing chamber and transfer chamber and alarger sealing plate to seal such an opening). Conventional slit valvestypically are not designed to accommodate large pressure differentials.Accordingly, a need exists for improved methods and apparatus forsealing an opening of a processing chamber, particularly when largepressure differentials are being employed.

SUMMARY OF THE INVENTION

In a first embodiment of the invention, a slit valve is provided that isadapted to seal an opening. The slit valve includes a valve housinghaving (1) a first wall; (2) a first opening formed in the first wall;(3) a second wall; and (4) a second opening formed in the second wall.The slit valve also includes a closure member having a sealing portionadapted to contact the second wall and seal the second opening, and abracing member moveable relative to the sealing portion and adapted tocontact the first wall. The slit valve further includes at least oneactuating mechanism adapted to (1) move the sealing portion toward thesecond wall and into contact with the second wall; and (2) move thebracing member away from the sealing portion and into contact with thefirst wall so as to brace the sealing portion against the second wall.

In a second embodiment of the invention, a method of sealing an openingis provided. The method includes providing a valve housing having (1) afirst wall; (2) a first opening formed in the first wall; (3) a secondwall; and (4) a second opening formed in the second wall. The methodfurther includes providing a closure member having a sealing portionadapted to contact the second wall and seal the second opening, and abracing member moveable relative to the sealing portion and adapted tocontact the first wall. The method also includes (1) moving the sealingportion toward the second wall and into contact with the second wall;and (2) moving the bracing member away from the sealing portion and intocontact with the first wall so as to brace the sealing portion againstthe second wall. Numerous other aspects are provided.

Other features and aspects of the present invention will become morefully apparent from the following detailed description, the appendedclaims and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1C illustrate an embodiment of an apparatus in accordance withthe present invention comprising a chamber isolation valve.

FIG. 2 is a perspective exploded assembly view of an inventive chamberisolation valve representing an exemplary embodiment of the chamberisolation valve of FIGS. 1A-1C.

FIGS. 3A-3F are sectional assembly side views of the chamber isolationvalve of FIG. 2 taken at various locations along a length of the chamberisolation valve.

FIG. 4 is a flowchart that illustrates an exemplary process for sealingthe first opening of the chamber isolation valve of FIG. 2.

FIG. 5 is a flowchart that illustrates an exemplary process for placingthe closure member of the chamber isolation valve of FIG. 2 in thelongitudinally retracted position of the closure member shown in FIG.3F.

FIG. 6 is a schematic representation of a slit valve system includingthe chamber isolation valve of FIG. 2 and a slit valve control moduleadapted to operate and/or coordinate functions of the chamber isolationvalve.

FIG. 7 is a schematic representation of a particular embodiment of theslit valve system of FIG. 6.

DETAILED DESCRIPTION

FIGS. 1A-1C illustrate an embodiment of an apparatus in accordance withthe present invention comprising a chamber isolation valve 101. Also,when considered in light of the discussion below, FIGS. 1A-1C illustratean embodiment of an inventive method for using the chamber isolationvalve 101 to seal an opening 102 (shown in phantom in FIG. 1A) to anadjacent processing chamber P (shown in phantom in FIG. 1A) so as topermit pressurization of the processing chamber P for processing of asubstrate contained therein.

The chamber isolation valve 101 may include a closure member 103 forsealing the processing chamber opening 102. In addition, the chamberisolation valve 101 may comprise a valve housing 105 within which atleast a portion of the closure member 103 may be movably disposed. Topermit the chamber isolation valve 101 to be used in conjunction with anopening of a processing chamber, the valve housing 105 of the chamberisolation valve 101 may be placed against the processing chamber, e.g.such that a seal (not shown) is formed between the valve housing 105 andthe processing chamber around the processing chamber opening to besealed.

The closure member 103 may include a sealing portion 107 for sealing theprocessing chamber opening 102. For example, the sealing portion 107 maybe utilized so as to seal the processing chamber opening 102 indirectly,e.g., by sealing an opening to the valve housing 105 that is alignedwith the processing chamber opening 102. Alternatively, the sealingportion 107 may be placed in direct contact (not shown) with theprocessing chamber P such that the sealing portion 107 seals around theprocessing chamber opening 102.

The closure member 103 may further include a bracing member 109 that ismovable relative to the sealing portion 107. For example, the bracingmember 109 may be adapted to extend away from and retract toward thesealing portion 107. Further, the bracing member 109 may be adapted tobrace or buttress the sealing portion 107, for example, when the sealingportion 107 is in position to seal the processing chamber opening 102 asdescribed above. Such an arrangement is inherently efficient in that itmay decrease and/or minimize the amount of force needed to counter apositive pressure within the processing chamber P, especially ascompared to commonly-utilized cantilevered arrangements (not shown).

To provide for convenient movement of the closure member 103 relative tothe processing chamber opening 102, the closure member 103 may alsocomprise an extended portion 111 extending from the sealing portion 107.In such an embodiment, an end of the extended portion 111 that is spacedaway from the sealing portion 107 may be adapted to be grasped and/ormanipulated, e.g. by an actuator (see FIG. 2) disposed inside or outsidethe valve housing 105, so as to enable the closure member 103 to bemoved as a unit (e.g. by moving both the sealing portion 107 and thebracing member 109 together via the extended portion 111). For example,the closure member 103 may be moved via the extended portion 111 towardand/or away from the processing chamber opening 102 (transverselybetween the respective configurations of the chamber isolation valve 101shown in FIGS. 1B and 1C or longitudinally between the respectiveconfigurations of the chamber isolation valve 101 shown in FIGS. 1A and1B).

Preferably, the extended portion 111 of the closure member 103 is fixedin relation to the sealing portion 107 of the closure member 103. Forexample, the sealing portion 107 and the extended portion 111 may be ofunitary construction as shown in FIG. 1A. Alternatively the extendedportion 111 may be fixedly coupled to the sealing portion 107.

The valve housing 105 may define an enclosure 113, a first opening 115to the enclosure 113, and a second opening 117 to the enclosure 113.Preferably, the first opening 115 and the enclosure 113 are alignedalong a common axis with the processing chamber opening 102 and aresized so as to permit passage of substrates through the valve housing105 and into and out of the processing chamber P. For example, the firstopening 115 may be spaced apart from the processing chamber opening 102and the second opening 117 may be disposed on the other side of theenclosure 113, adjacent the processing chamber opening 102 and on thecommon axis. In one or more embodiments, the second opening 117 may beplaced in pneumatic communication with the processing chamber opening102 such that the second opening 117 essentially comprises an extensionof the processing chamber opening 102.

The valve housing 105 may further comprise a rear plate 119 within whichthe first opening 115 is formed. The rear plate 119 may be adapted, andappropriately located, so as to permit the bracing member 109 to contactthe rear plate 119 and push against the rear plate 119 for bracing thesealing portion 107 of the closure member 103 during sealing (asdescribed further below).

The valve housing 105 may further comprise a front plate 121 withinwhich the second opening 117 is formed. The front plate 121 may beadapted, and appropriately located, so as to permit the sealing portion107 of the closure member 103 to contact the front plate 121 and sealaround the second opening 117. Alternatively, as discussed above, thesealing portion 107 may directly contact the processing chamber P toseal the opening 102.

In operation, as shown in FIG. 1A, the closure member 103 of the chamberisolation valve 101 is adapted to assume a retracted position relativeto the first and second openings 115, 117 wherein the closure member 103is spaced away from (e.g., below) the first and second openings 115,117. Such a configuration permits substrates to be passed through thevalve housing 105 and into and out of the processing chamber P.

As shown in FIG. 1A, in at least one embodiment, the enclosure 113 ofthe valve housing 105 may enclose the sealing portion 107 of the closuremember 103 while still permitting passage of substrates through thevalve housing 105. Also as shown in FIG. 1A, the enclosure 113 of thevalve housing 105 may enclose the sealing portion 107 and the bracingmember 109 with space to spare, e.g. so as to provide a first gap 123between the bracing member 109 and the rear plate 119, and a second gap125 between the sealing portion 107 and the front plate 121.

The closure member 103 may be moved relative to the valve housing 105 soas to assume a deployed position relative to the first and secondopenings 115, 117 as shown in FIG. 1B wherein the sealing portion 107 isdisposed between the first and second openings 115, 117. Preferablyduring such deployment, the first and second gaps 123, 125 aremaintained so as to reduce and/or eliminate particle-generating frictionand/or rubbing that might otherwise arise between the closure member 103and the valve housing 105. It will now be apparent that substrates (notshown) may no longer be passed through the valve housing 105, since theclosure member 103 blocks the path therethrough.

The closure member 103, which in FIG. 1B is shown in a retractedposition relative to the second opening 117 of the valve housing 105,may be moved into a deployed position relative to the second opening 117as shown in FIG. 1C. As shown in FIG. 1C, the sealing portion 107 of theclosure member 103 is in contact with the front plate 121, and may becaused to seal the second opening 117 of the valve housing 105.Preferably, and as demonstrated by the chamber isolation valve 101 shownin FIGS. 1B and 1C, relative motion between the sealing portion 107 ofthe closure member 103 and the front plate 121 of the valve housing 105leading to sealing of the second opening 117 is restricted to adirection that is normal to front plate 121, so as to reduce and/oreliminate the potential for particle generation via friction.

As may also be seen by comparing FIG. 1C to FIG. 1B, the chamberisolation valve 101 may be adapted to generate a separation force thatmoves the bracing member 109 relative to the sealing portion 107 so asto cause the bracing member 109 to move away from the processing chamberopening 102 (FIG. 1) and into contact with the rear plate 119 of thevalve housing 105. Alternatively, the bracing member 109 may be causedto contact a portion of the transfer chamber (not shown), or anotherstructural member. The chamber isolation valve 101 may then generate abracing force, also tending to urge the bracing member 109 away from thesealing portion 107, so as to brace or buttress the sealing portion 107of the closure member 103 against the front plate 121 of the valvehousing 105, or against the processing chamber P (FIG. 1), as the casemay be. Such a bracing force may be generated in any number of ways andat any number of locations relative to the closure member 103. Forexample, the bracing force may be both generated and applied directlybetween the bracing member 109 and the sealing portion 107, e.g. by apneumatic actuator (see FIG. 2) disposed or formed therebetween. Notethat in at least one embodiment of the invention, the bracing member 109does not seal the first opening 115.

FIG. 2 is a perspective exploded assembly view of an inventive chamberisolation valve 101 a representing an exemplary embodiment of thechamber isolation valve 101 of FIGS. 1A-1C. FIGS. 3A-3F are sectionalassembly side views of the chamber isolation valve 101 a taken atvarious locations along a length of the chamber isolation valve 101 aand which describe structural and operational aspects of the chamberisolation valve 101 a. Structural and functional descriptions appearingabove with reference to the chamber isolation valve 101 therefore alsoapply to the chamber isolation valve 101 a, with similar referencenumerals being used to indicate corresponding aspects (e.g., ofstructure) in the figures.

Referring to FIGS. 2 and 3A, the valve housing 105 may comprise an upperportion 127 and a lower portion 129 that is coupled to the upper portion127. The upper portion 127 may include a resilient element 130 (FIG. 3A)so as to permit the rear plate 119 of the valve housing 105 to be sealedagainst an external corresponding structure, such as a valve interfaceportion of a transfer chamber (not shown). The lower portion 129 mayinclude resilient element 131 (FIG. 3A) for sealing the lower portion129 of the valve housing 105 against the upper portion 127 of the valvehousing 105. The lower portion 129 may further include a first and asecond port 133 (FIGS. 2 and 3D) adapted to permit an extended portion111 of the closure member 103 to extend outward of the valve housing 105and to permit both longitudinal (e.g. vertical) and transverse (e.g.horizontal) movement of the closure member 103 relative to the valvehousing 105. More or fewer ports 133 may be specified as necessary or asdesired.

Referring to FIG. 2, the closure member 103 includes two extendedportions 111, each extended portion 111 being coupled to the sealingportion 107, and the chamber isolation valve 101 a being configured suchthat each extended portion 111 extends through a port 133. More or fewerextended portions 111 may be specified as necessary or as desired.

Referring to FIGS. 2 and 3A-3F, the chamber isolation valve 101 a maycomprise a deployment mechanism 134 for moving the closure member 103,e.g. relative to the valve housing 105 and/or the processing chamberopening 102 (FIG. 1A). For example, the deployment mechanism 134 mayinclude one or more first actuators 135 (FIGS. 2 and 3A) for moving theclosure member 103 between longitudinally retracted and longitudinallydeployed positions of the closure member 103, shown respectively inFIGS. 3F and 3D. The first actuator 135 may be one of many differenttypes of suitable devices. For example, a pneumatically-driven linearactuator such as is embodied by the first actuator 135 of FIGS. 2 and 3Awould be suitable, as would be a belt- or screw-driven actuator.

The deployment mechanism 134 may further comprise one or more externalbellows 137 (FIG. 2) for protecting the enclosure 113 (FIG. 3D) of thevalve housing 105 against intrusion of contaminants through the ports133. Each external bellows 137 corresponds to and is adapted to surrounda separate extended portion 111 of the closure member 103. Where more orfewer extended portions 111 exist, the number of external bellows 137may increase or decrease accordingly. Each external bellows 137 mayinclude a first mounting flange 139 mounted to the valve housing 105around the port 133 through which the corresponding extended portion 111extends.

The deployment mechanism 134 may further include one or more secondactuators 141 (FIGS. 2 and 3C) for moving the closure member 103 betweentransversely retracted and transversely deployed positions of theclosure member 103, shown respectively in FIGS. 3D and 3E. Each secondactuator 141 may be mounted to a first support plate 143 which may inturn be movably mounted to the valve housing 105 via the first actuator135. Each second actuator 141 may be one of many different suitabledevices. For example, a pneumatically-driven linear actuator, such as isembodied by the second actuator 141 of FIGS. 2 and 3C, would besuitable, as would be a belt- or screw-driven actuator.

The deployment mechanism 134 may be adapted to guide the first supportplate 143 as the first actuator 135 moves the first support plate 143longitudinally relative to the valve housing 105. For example, a firstand a second support 149 may be affixed to and extend from the valvehousing 105, and the first support plate 143 may be slidably coupled toeach support 149, e.g., via a rail 151 preferably fixedly coupled toeach support 149, and a first and second pair of trucks 153. Each pairof trucks 153 may be fixedly coupled to the first support plate 143 andmovably coupled to a rail 151 so as to permit longitudinal movement ofthe first support plate 143.

Referring to FIGS. 2, 3C and 3D, the deployment mechanism 134 mayfurther include one or more brackets 145, each bracket 145 being securedto an end of a extended portion 111 that is spaced apart from thesealing portion 107 of the closure member 103. The deployment mechanism134 may also include a second support plate 147, the second supportplate 147 being movably mounted to the first support plate 143 (and/orto the valve housing 105) via the second actuator 141. Each bracket 145may be coupled to the second support plate 147 to provide a means bywhich the deployment mechanism 134 may manipulate and/or move theclosure member 103 (e.g. longitudinally, or transversely, or acombination thereof).

The deployment mechanism 134 may be adapted both to guide the secondsupport plate 147 as the second actuator 141 moves the second supportplate 147 transversely relative to the first support plate 143 and thevalve housing 105, and to isolate the transversely-operating secondactuator 141 from the vertical force represented by the combined weightof the closure member 103, the second support plate 147 and the brackets145 (e.g. so as to facilitate smooth transverse translation of theclosure member 103 relative to the valve housing 105). For example, asshown in FIGS. 2 and 3B, the deployment mechanism 134 may furthercomprise bearings 155 extending from sides of the first support plate143, and each bracket 145 may comprise a guide slot 157 adapted toaccommodate a roller portion 159 of one of the bearings 155. As such,while the second support plate 147 is moving transversely relative tothe first support plate 143, the bearings 155 and the first supportplate 143 may be caused to bear substantially all of the weight of theclosure member 103, the brackets 145 and the second support plate 147while still allowing that subassembly to smoothly translate viaoverturning (rolling) communication between the bearing roller portions159 and-the bracket guide slots 157.

For instances in which the first opening 115 of the valve housing 105 isrelatively long, as with the chamber isolation valve 101 a of FIG. 2,bracing member 109 may include a brace plate 161 that is similarlyelongated. The brace plate 161 may comprise a first side 163 (FIG. 3C)that faces toward the sealing portion 107, on which a plurality ofmounting bosses 165 (FIG. 3B) may be provided. Each of the plurality ofmounting bosses 165 may be adapted to extend into a respective one of aplurality of pockets 167 (FIG. 2, see also FIG. 3B) formed within anon-sealing side 169 (FIG. 2) of the sealing portion 107. A respectiveone of an equivalent plurality of drive plates 171 (FIG. 2) may bedisposed within each pocket 167 (see FIG. 3D) and coupled, preferablyfixedly, to the mounting boss 165 of the brace plate 161 extendingtherein. A subassembly may thereby be formed comprising the brace plate161 as well as each drive plate 171 coupled to the brace plate 161 viathe mounting bosses 165.

The closure member 103 may be adapted to move the bracing member 109back and forth between the (transversely) retracted position shown inFIG. 3D and the deployed or extended position shown in FIG. 3E. Forexample, an actuating device may be employed within the bracing member109 and/or the sealing portion 107 of the closure member 103 (e.g., soas to only minimally enlarge the overall size of the closure member103). For instance, the closure member 103 may comprise at least onebracing actuator 173 (FIGS. 2 and 3E) as described below with referenceto FIGS. 2 and 3B-3F.

When the first opening 115 is relatively long, as with the chamberisolation valve 101 a of FIG. 2, the closure member 103 may include aplurality of bracing actuators 173 (e.g., depending on the magnitude ofbracing force that is required to be applied to the sealing portion 107via the bracing member 109 and/or the room available on the non-sealingside 169 of the sealing portion 107 to form pockets 167). Each bracingactuator 173 may be built into, and/or integrated within the closuremember 103 so as to be comprised of portions of some of the componentsof the closure member 103 already described above (e.g., a pocket 167 ofthe sealing portion 107, and a drive plate 171 of the bracing member109). In addition, each bracing actuator 173 may comprise a drive platebellows 175 (FIG. 3D) that includes a mounting flange 177 coupled to thenon-sealing side 169 of the sealing portion 107 (e.g., around a pocket167 of the sealing portion 107), and an extensible wall portion 179attached to the mounting flange 177 and extending into the pocket 167,within which the extensible wall portion 179 is attached to a driveplate 171.

With reference to FIG. 3E, each bracing actuator 173 may comprise apressure cell 181 comprising a pocket 167 of the sealing portion 107(see also FIG. 3B), a drive plate 171 of the bracing member 109, theextensible wall portion 179 of the drive plate bellows 175, and themounting flange 177 (FIG. 3D) of the drive plate bellows 175. Thepressure cell 181 may be expanded via an external source of pressurizedgas (not shown) to force the bracing member 109 against the rear plate119. For example, FIG. 3E illustrates a configuration of the chamberisolation valve 101 a in which the sealing portion 107 of the closuremember 103 is deployed against the front plate 121 of the valve housing105, the bracing member 109 of the closure member 103 is deployedagainst the rear plate 119 of the valve housing 105, the extensible wallportion 179 of each drive plate bellows 175 is relatively compressed,and the volume of the pressure cell 181 is relatively large.

Alternatively, the pressure cell 181 may be contracted via an externalsource of vacuum pressure. For example, FIG. 3D illustrates aconfiguration of the chamber isolation valve 101 a in which the bracingmember 109 is retracted within a pocket 167 (FIG. 3B) of the sealingportion 107, the extensible wall portion 179 of the drive plate bellows175 is relatively extended, and the volume of the pressure cell 181(FIG. 3E) is relatively small. As will be explained further below, eachbracing actuator 173 may comprise one such pressure cell 181 and mayactuate (e.g., move/position/urge the bracing member 109) via changes inthe volume of the pressure cell 181 and/or in the pressure (e.g., airpressure or fluid pressure) within the pressure cell 181.

Each bracing actuator 173 may be energized pneumatically. For example,each pocket 167 may be pneumatically coupled via a conduit 183 (FIG. 3B)that penetrates the walls of each of the pockets 167. Thus when thepressure cell 181 of one bracing actuator 173 of the closure member 103is subjected to increased air or fluid pressure for expansion, or tovacuum pressure for contraction as the case may be, the pressure cell181 of each bracing actuator 173 will tend to be similarly energized. Assuch the collective force exerted by the bracing actuators 173 may movethe bracing member 109 relative to (e.g., toward or away from) thesealing portion 107, according to the pressure existing in the conduit183.

The closure member 103 may be adapted to expose the conduit 183 to asource of vacuum pressure (not shown) for retracting the bracing member109 within the sealing portion 107, e.g., so as to prevent contactbetween the bracing member 109 and the valve housing 105 when theclosure member 103 is in the longitudinally retracted position of FIG.3F, or is being moved into or out of same. (The sealing portion 107 ofthe closure member 103 may be similarly retracted from the front plate121). The closure member 103 may also be adapted to expose the conduit183 to a source of pressurized gas (not shown) for extending the bracingmember 109 away from the sealing portion 107 and/or to cause the bracingmember 109, when fully extended, to push against the rear plate 119 ofthe valve housing 105 so as to brace the sealing portion 107 against thefront plate 121 of the valve housing 105 as shown in FIG. 3E.

Exposure of the conduit 183 to a source of vacuum pressure or ofpressurized gas can be accomplished in any of a number of ways. Forexample, one or both brackets 145 can include a socket 185 (FIG. 2)adapted to receive a pressure fitting (not shown), e.g., an end fittingof a pressure hose. The pressure fitting (not shown) may be adapted tomate with a pressure port 187 (FIG. 3E) formed within the extendedportion 111 of the closure member 103 that is in communication with anextended conduit 189 (FIG. 3C) also formed within the extended portion111 and leading to a sealing portion interface 191 (FIG. 3C) of theextended portion 111. The sealing portion interface 191 may be made toseal against an extended portion interface 193 of the sealing portion107. A resilient element 195 may provide for a seal between the twointerfaces. A feeder conduit 197 within the sealing portion 107 may leadfrom the extended portion interface 193 to the conduit 183 of thesealing portion 107. Such an arrangement provides a convenient means forpneumatically actuating the bracing actuators 173 of the closure member103 and for exercising positive control (e.g., applying either vacuum orpressurized gas as necessary) over the position of the bracing member109 relative to the sealing portion 107 (e.g., at all times). Otherconfigurations for applying vacuum or pressurized gas to the bracingactuators 173 also may be employed.

It should also be noted that the extensible wall portions 179 of each ofthe drive plate bellows 175 are compressed during expansion of thepressure cells 181. Such an arrangement may subject the extensible wallportions 179 to less stress and fatigue than would be the case if theextensible wall portions 179 were expanded during pressure cellexpansion, thus increasing the useful life of the drive plate bellows175. The opposite arrangement may be employed.

It is further noted that in one embodiment each of the extended portions111 of the closure member 103 may contact (see FIG. 3E) an inner surface154 (FIG. 3D) of the first mounting flange 139 of an external bellows137 as the sealing portion 107 of the closure member 103 contacts thefront plate 121 of the valve housing 105. Such an arrangement may assistin providing a positive, self-aligning limit to the extent to which theclosure member 103 moves toward the front plate 121 of the valve housing105 (as described below). For instance, the position of the closuremember 103 within the valve housing 105 when contact is establishedbetween the extended portion 111 and the first mounting flanges 139 maycorrespond to a desired initial degree of compression of a resilientsealing element (not shown) between the sealing portion 107 of theclosure member 103 and the front plate 121, such that any furthercompression that may be required may be provided by the bracing member109 bracing the sealing portion 107 against the front plate 121. Inother embodiments, the extended portions 111 may remain out of contactwith the inner surface 154 of the bellows 137 when the sealing portion107 of the closure member 103 contacts the front plate 121.

FIG. 4 is a flowchart that illustrates an exemplary process 400 forsealing the first opening 115 of the chamber isolation valve 101 a.Referring to FIG. 4, the process 400 may begin at a step 401. At a step402, the process 400 either proceeds to a step 403 or a step 404depending on the longitudinal position of the closure member 103 (FIG.2). If the closure member 103 is in the longitudinally retractedposition illustrated in FIG. 3F, the process 400 proceeds to step 403.

At the step 403, the closure member 103 is moved from the longitudinallyretracted position of FIG. 3F to the longitudinally deployed position ofthe closure member 103 illustrated by FIG. 3D. For example, the firstactuator 135 of the deployment mechanism 134 may be caused to elevatethe closure member 103 from the longitudinally retracted position ofFIG. 3F to the longitudinally deployed position of FIG. 3D. In one ormore embodiments of the inventive method, before, during and/or afterthe above-described elevation of the closure member 103, the deploymentmechanism 134 maintains the second gap 125 (FIG. 1A) and one or more ofthe bracing actuators 173 maintains the first gap 123 (FIG. 1A) betweenthe closure member 103 and the valve housing 105 to protect againstrubbing and/or particle generation during movement of the closure member103. Accordingly, in some such embodiments, the second actuators 141 ofthe deployment mechanism 134 are actuated to retain the closure member103 in a transversely retracted position away from the front plate 121of the valve housing 105.

At the conclusion of the step 403, the closure member 103 will be in thevertically deployed position of FIG. 3D. As such, the process 400proceeds to a step 404.

At the step 404, the closure member 103 is transversely deployed, e.g.,is moved from the transversely retracted position of the closure member103 of FIG. 3D to the transversely deployed position of the closuremember 103 illustrated in FIG. 3E. For example, one or more of thesecond actuators 141 of the deployment mechanism 134 (and/or one or moreof the bracing actuators 173) may be caused to move the closure member103 from the transversely retracted position of the closure member 103of FIG. 3D to the transversely deployed position of FIG. 3E. Bydeactivating (e.g., depressurizing) the second actuators 141, theextended portions 111 may be transversely movable, and expansion of oneor more of the bracing actuators 173, spring biasing of the extendedportions 111 or the closure member 103 or the like may move the sealingportion 107 toward the front plate 121. In one or more embodiments ofthe inventive method, the above transverse deployment of the closuremember 103 results in the sealing portion 107 of the closure member 103being moved into contact with the front plate 121 of the valve housing105. In some such embodiments and/or in other embodiments, theabove-described transverse deployment of the closure member 103 resultsin the extended portions 111 of the closure member 103 contactingcorresponding inner surfaces 154 of the first mounting flanges 139 ofthe external bellows 137.

Proceeding to a step 405 of the process 400, the bracing member 109 ofthe closure member 103 is transversely deployed, e.g., is moved to atransversely deployed position of the bracing member 109 illustrated inFIG. 3E. For example, one or more of the bracing actuators 173 (FIG. 2)of the closure member 103 may be caused to move the bracing member 109away from a transversely retracted position of the bracing member 109against and/or within the sealing portion 107 (e.g., as illustrated inFIG. 3D), to the transversely deployed position of FIG. 3E.

In one or more embodiments of the inventive method, the step 405 beginsonly after the step 404 is complete. In other embodiments, the step 405and the step 404 are performed simultaneously and/or both steps arebegun before either is complete. In still further embodiments, the step404 begins only after the step 405 has begun. Additionally, in one ormore embodiments of the inventive method, before, during, and/or afterthe above-described transverse deployments of the closure member 103 andthe bracing member 109 of the closure member 103, the deploymentmechanism 134 is employed to maintain the closure member 103 in thelongitudinally deployed position of the closure member 103 (FIG. 3E).For example, the first actuator 135 may remain activated after elevatingthe closure member 103 (see step 402).

Proceeding to a step 406 of the process 400, the sealing portion 107 isbraced against the front plate 121 to seal the first opening 115 formedtherein. For example, the pressure in the pressure cells 181 of eachbracing actuator 173 may be increased from what may have been arelatively low pressure sufficient to move the bracing member 109 intoplace against the rear plate 119 (see the step 405) to a relatively highpressure commensurate with the anticipated magnitude of pressure forcesto be exerted by the pressurized chamber P. Alternatively, if a pressureused to expand the pressure cells 181 in the step 405 is high enough toresist the anticipated pressure forces, or if the pressure was increasedgradually or step-wise during the step 405 to an adequately highpressure, that same pressure may be maintained for as long as bracingforce is required.

With the closure member 103 being both longitudinally and transverselydeployed, the bracing member 109 being transversely deployed and thesealing portion 107 being braced against the front plate 121 so as toseal the first opening 115, the process 400 ends at a step 407.

The process 400 may alternatively begin with one or more steps to ensurethat the first and second gaps 123, 125 between the closure member 103and the valve housing 105 exist prior to the closure member 103 beinglongitudinally deployed (e.g., elevated) by the first actuator 135 ofthe deployment mechanism 134. For example, one or more of the bracingactuators 173 may be employed in a direction opposite the bracingdirection, e.g., via the application of vacuum pressure, to ensure thebracing member 109 remains retracted against and/or within the sealingportion 107 (and away from the rear plate 119 of the valve housing 105)during longitudinal deployment of the closure member 103. Further, oneor more of the second actuators 141 may be employed in a directionopposite the sealing direction, e.g., via the application of positivepressure (with movement in the sealing direction occurring, e.g., by theforce of a biasing element, such as a coil spring (not shown) or byexpansion of the pressure cells 181), to ensure the sealing portion 107of the closure member 103 remains retracted away from the front plate121 of the valve housing 105 during longitudinal deployment of theclosure member 103.

FIG. 5 is a flowchart that illustrates an exemplary process 500 forplacing the closure member 103 of the chamber isolation valve 101 a inthe longitudinally retracted position of the closure member 103 shown inFIG. 3F. Referring to FIG. 5, the process 500 may begin at a step 501.At a step 502, the process 500 either proceeds to a step 503 or a step504 depending on the transverse position of the bracing member 109 (FIG.2). If the bracing member 109 is not in a transversely retractedposition, the process 500 proceeds to the step 503.

At the step 503, the bracing member 109 is transversely retracted, e.g.,moved to a transversely retracted position such as is shown in FIG. 3D.For example, one or more of the bracing actuators 173 may be caused tomove the bracing member 109 from a transversely deployed position of thebracing member 109, such as is shown in FIG. 3E, to the transverselyretracted position as shown in FIG. 3D.

Proceeding to the step 504, the process 500 either proceeds to the step505 or a step 506 depending on the transverse position of the closuremember 103 (FIG. 2). If the closure member 103 is not in a transverselyretracted position, the process 500 proceeds to step 505.

At the step 505, the closure member 103 is transversely retracted, e.g.,moved to a transversely retracted position such as is shown in FIG. 3D.For example, one or more of the second actuators 141 may be caused tomove the closure member 103 from a transversely deployed position of theclosure member 103, such as is shown in FIG. 3E, to the transverselyretracted position as shown in FIG. 3D.

In one or more embodiments of the process 500, two or more of the steps502, 503, 504 and 505 may occur simultaneously or in a different order.Additionally, the step 505 need not begin only after the step 503 iscomplete. Also, in one or more embodiments of the process 500, before,during and after the retraction of either or both the bracing member 109and the closure member 103, the deployment mechanism 134 may be employedto actively retain the closure member 103 in the vertically deployedposition of the closure member 103 (FIG. 3E). For example, the firstactuator 135 of the deployment mechanism 134 may be continuouslyactivated for this purpose.

Proceeding to the step 506, the closure member 103 is moved to thelongitudinally retracted position of the closure member 103 as shown inFIG. 3F. For example, the first actuator 135 of the deployment mechanism134 may be caused to move the closure member 103 from the longitudinallydeployed position as shown in FIG. 3D to the longitudinally retractedposition shown in FIG. 3F. In one or more embodiments of the process500, before, during, and/or after the above-described retraction of theclosure member 103, the deployment mechanism 134 and one or more of thebracing actuators 173 may maintain the first and second gaps 123, 125(FIG. 1A) between the closure member 103 and the valve housing 105 toprotect against rubbing and/or particle generation during longitudinalmovement of the closure member 103. For example, in some suchembodiments, the second actuators 141 may be prevented from moving theclosure member 103 transversely toward the front plate 121 of the valvehousing 105. Additionally, in one or more embodiments the bracingactuators 173 may be prevented from moving the bracing member 109transversely toward the rear plate 119 of the valve housing 105. Aswell, in one or more embodiments, one or more of the bracing actuators173 may be activated, e.g., via application of vacuum pressure, tomaintain a retracted position of the bracing member 109 against/withinthe sealing portion 107 during longitudinal retraction of the closuremember 103.

The closure member 103 being both longitudinally and transverselyretracted, the chamber isolation valve 101 a is now configured to permitpassage of substrates back and forth through the valve housing 105 ofthe chamber isolation valve 101 a, and the process 500 ends at a step507. Where it is advantageous or desirable, additional steps may betaken to ensure the closure member 103 remains spaced apart from thevalve housing 105, even when retracted and not moving. For example, oneor more of the bracing actuators 173 and/or one or more of the secondactuators 141 may be continuously activated to maintain the first and/orsecond gaps 123, 125 (FIG. 1A).

As relates to the processes 400, 500 of FIGS. 4 and 5, in someembodiments of the chamber isolation valve 101 a, the first actuator 135is adapted to actuate via the application of positive pressure duringboth longitudinal deployment and longitudinal retraction of the closuremember 103. In some other embodiments of the chamber isolation valve 101a, the first actuator 135 may be adapted to actuate via positivepressure during longitudinal deployment with gravity being employed forvertical retraction. In further embodiments of the chamber isolationvalve 101 a, each bracing actuator 173 may be adapted to actuate via aspring default during transverse deployment of the closure member 103,and in some such embodiments each second actuator 141 may be adapted toactuate via positive pressure during transverse retraction of theclosure member 103 (e.g., for assurance of maintaining a transverseretraction of the closure member 103 during longitudinal movement of theclosure member 103). In still further embodiments of the chamberisolation valve 101 a, each bracing actuator 173 may be adapted toactuate via positive pressure during transverse deployment of thebracing member 109 and via vacuum pressure (e.g., no spring default)during transverse retraction of the bracing member 109 (e.g., to avoidhaving to overcome the force of a spring default when deploying thebracing member 109). Other configurations may be employed.

FIG. 6 is a schematic representation of a slit valve system 600including the chamber isolation valve 101 a of FIG. 2 and a slit valvecontrol module 601 adapted to operate and/or coordinate functions of thechamber isolation valve 101 a. For example, the slit valve controlmodule 601 may be adapted to interact with the chamber isolation valve101 a so as to perform the process 400 illustrated by the flow chart ofFIG. 4 and/or the process 500 illustrated by the flow chart of FIG. 5.

The slit valve control module 601 may comprise an input/output module603 adapted to generate and/or receive signals. For example, theinput/output module 603 may be adapted to:

(1) determine whether the closure member 103 is in a longitudinallyretracted position as illustrated in FIG. 3F;

(2) generate and transmit an electrical signal along a first signalconductor 605 corresponding to the closure member 103 being in thelongitudinally retracted position of FIG. 3F;

(3) illuminate an indicator light (e.g., a green L.E.D.) correspondingto the closure member 103 being in the longitudinally retracted positionof FIG. 3F;

(4) determine whether the closure member 103 is in a longitudinallydeployed position as illustrated in FIG. 3D;

(5) generate and transmit an electrical signal along a second signalconductor 607 corresponding to the closure member 103 being in thelongitudinally deployed position of FIG. 3D;

(6) illuminate an indicator light (e.g., a red L.E.D.) corresponding tothe closure member 103 being in the longitudinally deployed position ofFIG. 3D;

(7) determine whether the bracing member 109 is in a transverselydeployed position as illustrated on FIG. 3E;

(8) generate and transmit an electrical signal along a third signalconductor 609 corresponding to the bracing member 109 being in thetransversely deployed position of FIG. 3E;

(9) prevent the signal (5) above from being generated and transmitted,and the indicator light of (6) above from being illuminated, until thebracing member 109 has been determined to be in a transversely deployedposition as in (7) above;

(10) receive an electrical signal along a fourth signal conductor 611,e.g., so as to cause and/or permit the slit valve control module 601 tooperate the chamber isolation valve 101 a so as to perform the process400 described above with reference to FIG. 4 (e.g., seal the firstopening 115 of the chamber isolation valve 101 a as illustrated in FIG.3E);

(11) receive an electrical signal along a fifth signal conductor 613,e.g., so as to cause and/or permit the slit valve control module 601 tooperate the chamber isolation valve 101 a so as to perform the process500 described above with reference to FIG. 5 (e.g., place the closuremember 103 in the longitudinally retracted position of the closuremember 103 as illustrated in FIG. 3F);

(12) control and direct power to one or more pneumatic switches of theslit valve control module 601 (not shown) adapted to selectivelyreconfigure connections between and/or among a plurality of pneumaticconduits having a connection to the slit valve control module 601, suchas:

-   -   (a) a vacuum source conduit 615;    -   (b) a pressurized gas source conduit 617;    -   (c) an ambient (atmospheric) exhaust conduit 619;    -   (d) a brace actuation conduit 621;    -   (e) a clamp actuation conduit 623;    -   (f) a closure member lowering conduit 625;    -   (g) a closure member elevating conduit 627;

(13) detect the presence of elevated pressure (e.g., pressurization) inthe brace actuation conduit 621;

(14) perform the function of (7) above at least in part via the functionof (13) above; and/or (15) detect the presence of depressed pressure(e.g., vacuum) in the brace actuation conduit 621.

The slit valve control module 601 may also be adapted to perform thefollowing functions:

(16) selectively connecting the pressurized gas source conduit 617 tothe brace actuation conduit 621, e.g., so as to actuate each bracingactuator 173 and thereby move the bracing member 109 into thetransversely deployed position illustrated in FIG. 3E;

(17) selectively connecting the vacuum source conduit 615 to the braceactuation conduit 621, e.g., so as to actuate each bracing actuator 173and thereby move the bracing member 109 into the transversely retractedposition illustrated in FIG. 3D;

(18) positively preventing the function of (17) above from occurringwhile the pneumatic connection of (16) above exists;

(19) positively preventing the function of (16) above from occurringwhile the pneumatic connection of (17) above exists;

(20) selectively connecting the pressurized gas source conduit 617 tothe clamp actuation conduit 623, e.g., so as to actuate each secondactuator 141 of the deployment mechanism 134 and thereby move theclosure member 103 into the transversely retracted position illustratedin FIG. 3D (e.g., by defeating a spring default tending to deploy theclosure member 103);

(21) selectively connecting the ambient exhaust conduit 619 to the clampactuation conduit 623, e.g., so as to cease actuating each secondactuator 141 of the deployment mechanism 134 and to allow a springdefault (e.g., built into each deployment mechanism 134) or action ofthe bracing actuators 173 to dominate, thereby moving the closure member103 into the transversely deployed position illustrated in FIG. 3E;

(22) selectively connecting the pressurized gas source conduit 617 tothe closure member lowering conduit 625, e.g., so as to actuate thefirst actuator 135 (FIG. 3A) and thereby move the closure member 103into the longitudinally retracted position illustrated in FIG. 3F;

(23) selectively connecting the ambient exhaust conduit 619 to theclosure member elevating conduit 627, e.g., so as to facilitate thefunction of (22) above;

(24) selectively connecting the pressurized gas source conduit 617 tothe closure member elevating conduit 627, e.g., so as to actuate thefirst actuator 135 (FIG. 3A) and thereby move the closure member 103into the longitudinally deployed position illustrated in FIG. 3D;

(25) selectively connecting the ambient exhaust conduit 619 to theclosure member lowering conduit 625, e.g., so as to facilitate thefunction of (24) above;

(26) simultaneously performing (22) and (23) above;

(27) simultaneously performing (24) and (25) above;

(28) selectively switching from (26) above to (27) above;

(29) selectively switching from (27) above to (26) above;

(30) simultaneously performing (17) and (20) above;

(31) simultaneously performing (16) and (21) above;

(32) selectively switching from (30) above to (31) above;

(33) selectively switching from (31) above to (30) above;

(34) positively preventing (16) and (21) from occurring while thepneumatic connection of (22) exists;

(35) positively preventing (16) and (21) from occurring unless theclosure member 103 is in the vertically deployed position illustrated inFIG. 3D;

(36) positively preventing (28) and (29) above from occurring unless thepneumatic connection of (17) above exists;

(37) defaulting to (31) upon loss of power to the slit valve controlmodule 601;

(38) performing the process 400 of FIG. 4 by performing (28), (27),(35), (16), (21) and (36) above;

(39) performing the process 400 of FIG. 4 by performing (28), (27),(35), (16), (21), (36), (32) and (31) above;

(40) performing the process 500 of FIG. 5 by performing (36), (20),(17), (29), (22), (23), (26), and (34) above; and/or

(41) performing the process 500 of FIG. 5 by performing (36), (33),(20), (17), (29), (23), (26), (34), and (30) above.

Numerous other functions also or alternatively may be performed.

FIG. 7 is a schematic representation of a particular embodiment 600 a ofthe slit valve system 600 of FIG. 6 comprising the chamber isolationvalve 101 a of FIG. 2 and a particular embodiment 601 a of the slitvalve control module 601, wherein the slit valve control module 601 a isshown in more detail. Referring to FIG. 7, the slit valve control module601 a is adapted to perform the functions 1-41 as described above. Theaspects/structure of the slit valve control module 601 a adapted toperform those functions will be introduced and explained in the generalorder of the functions.

Functions 1-3 may be encompassed in a first position switch 629, a firstindicator light 631, and the first signal conductor 605. The firstposition switch 629 may be configured so as to be normally open, and maybe installed within or adjacent the chamber isolation valve 101 a suchthat it is actuated or closed when the closure member 103 reaches theFIG. 3F longitudinally retracted position. The first indicator light 631can be a signal to a human operator. The first signal conductor 605 cancarry a signal to a remote controller (not shown). Other uses for thefirst indicator light 631 and/or the first signal conductor 605 arepossible.

Functions 4-6 may by similarly encompassed in a second position switch635, a second indicator light 637, and the second signal conductor 607.The second position switch 635 may be configured so as to be normallyopen, and may be installed within or adjacent the chamber isolationvalve 101 a such that it is actuated or closed when the closure member103 reaches the FIG. 3D longitudinally deployed position. The secondindicator light 637 and the second signal conductor 607 may functionsimilarly to the first indicator light 631 and the first signalconductor 605.

Function 7 may be encompassed in pressure switch 641. The pressureswitch 641 may be configured so as to be normally open, and may bepneumatically coupled to the brace actuation conduit 621 (e.g., via anorifice 643 adapted to slowly equalize pressure on either side of theorifice 643) so as to be actuated or closed when the brace actuationconduit 621 is at positive pressure compared to ambient pressure. Sincepositive pressure in the brace actuation conduit 621 leads to transversedeployment of the bracing member 109 via actuation of each bracingactuator 173, and the orifice 643 may be actuated so as to equalizepressure only after the bracing member 109 has deployed, the pressureswitch 641 may perform function 7.

Functions 8 and 9 may be encompassed by the third signal conductor 609and the fact that the pressure switch 641 must be closed for the secondindicator light 637 to light up or for the third signal conductor 609 toreceive power.

Functions 10 and 11 may be encompassed by the fourth signal conductor611 and the fifth signal conductor 613 respectively.

Function 12 may be encompassed by the fourth signal conductor 611 andthe fifth signal conductor 613, which may be adapted to receive a signal(e.g., in the form of +24V or another power level signal), as describedbelow.

Function 13 may be encompassed in the pressure switch 641, and function14 is self-explanatory.

Function 15 may be encompassed in a vacuum switch 651. The vacuum switch651 may be configured so as to be normally open, and may bepneumatically coupled to the brace actuation conduit 621 (e.g., via theorifice 643) so as to be actuated or closed when the brace actuationconduit 621 is at vacuum pressure compared to the ambient.

Function 16 may be encompassed in a master pressure source valve 653.The master pressure source valve 653 may be configured so as to benormally closed, and may connect the brace actuation conduit 621 withthe pressurized gas source conduit 617. The master pressure source valve653 may be further configured so as to be actuated or opened whenexposed at an actuation port to positive pressure via a pneumaticconduit 655. The pneumatic conduit 655 may be selectively connectedeither to the pressurized gas source conduit 617 or the ambient exhaustconduit 619 via a first flow regulator 657 (as well as through a pair ofpneumatic switching connectors as will be explained below).

Function 17 may be encompassed in a master vacuum source valve 659. Themaster vacuum source valve 659 may be configured so as to be normallyclosed, and may connect the brace actuation conduit 621 with the vacuumsource conduit 615. The master vacuum source valve 659 may be furtherconfigured so as to be actuated or opened when exposed at an actuationport to positive pressure via a pneumatic conduit 661. The pneumaticconduit 661 may be selectively connected either to the pressurized gassource conduit 617 or the ambient exhaust conduit 619 via a second flowregulator 663 (as well as through a pneumatic switching connector aswill be explained below).

The slit valve control module 601 a may comprise a first pneumaticswitching connector 665, a second pneumatic switching connector 667, anda third pneumatic switching connector 669, all adapted to participate inthe interface described in the above described function 12. The firstpneumatic switching connector 665 and the second pneumatic switchingconnector 667 are adapted to establish and selectively vary thepneumatic connection configuration between and/or among five separatepneumatic conduits (two of which are always common with the ambientexhaust conduit 619, and one of which is always common with thepressurized gas source conduit 617), and the second pneumatic switchingconnector 667 is adapted to establish and selectively vary the pneumaticconnection configuration between three separate pneumatic conduits (oneof which is always common with the ambient exhaust conduit 619).

The second pneumatic switching connector 667 is adapted to assumepneumatic configuration A by default, wherein the default mechanism maybe, e.g., a spring, and is adapted to selectively assume pneumaticconfiguration B, e.g., via high-side voltage being applied to anactuation coil adapted to shift pneumatic configuration B into theposition occupied by configuration A as shown in FIG. 7. The thirdpneumatic switching connector 669 is adapted to assume pneumaticconfiguration C by default, wherein the default mechanism may be, e.g.,a spring, and is adapted to selectively assume pneumatic configuration Das shown in FIG. 7, e.g., via positive pressure being applied to apneumatic actuation mechanism 671 and the pneumatic actuation mechanism671 thereby actuating so as to shift pneumatic configuration D into theposition shown (e.g., moving configuration C out and movingconfiguration D in). The first pneumatic switching connector 665 isadapted to selectively assume either pneumatic configuration E, as shownin FIG. 7, or pneumatic configuration F, e.g., via two differenthigh-side conductors (e.g., of +24V) being applied to respectiveactuation coils that are adapted to move the first pneumatic switchingconnector 665 from configuration E to configuration F, or fromconfiguration F to configuration E, as the case may be.

The slit valve control module 601 a may further include additionalhigh-side voltage conductors 673, 675 and 677, return or groundconductors 679, 681, 683 and 685, and a third position switch 687. Thethird position switch 687 may be configured so as to be normally closed,and may be installed within or adjacent the chamber isolation valve 101a such that it is actuated or opened when the closure member 103 reachesthe FIG. 3D longitudinally deployed position.

It will be apparent to those skilled in the art upon reading the presentapplication and reviewing the figures of the present application,especially FIG. 7, that the slit valve control module 601 a is adaptedto perform the above-described functions 16-41 via selectively receivinga high-side voltage signal along the fourth signal conductor 611 or thefifth signal conductor 613, and permitting the remaining elements of theslit valve control module 601 a to function as described above accordingto the schematic of FIG. 7. For example, the master vacuum source valve659 and the master pressure source valve 653 are adapted to open in amutually exclusive manner, preventing the simultaneous application ofvacuum pressure and positive pressure to the brace actuation conduit 621and each bracing actuator 173. As well, the circuits between the fourthsignal conductor 611 and the return or ground conductor 683, and betweenthe fifth signal conductor 613 and the return or ground conductor 683,are incapable of being closed unless and until the brace actuationconduit 621 is being exposed to vacuum pressure via the master vacuumsource valve 659, and the vacuum switch 651 is thereby closed (thispermits switching from configuration E to configuration F, or viceversa, in the first pneumatic switching connector 665). Additionally,the third pneumatic switching connector 669 may not assume configurationD unless positive pressure is received at the pneumatic actuationmechanism 671, and the latter is not possible unless the first pneumaticswitching connector 665 is in configuration E as shown. Still further,the third position switch 687, shown open in FIG. 7, is normally closed,causing the second pneumatic switching connector 667 to remain inconfiguration B (resulting in vacuum pressure being applied to the braceactuation conduit 621 and the bracing member 109 to remain in thetransversely retracted position of FIG. 3F) until the closure member 103reaches the longitudinally deployed position of FIG. 3D, at which timethe third position switch 687 opens, triggering the spring default ofthe second pneumatic switching connector 667, and causing the secondpneumatic switching connector 667 to switch to configuration A. Otherconfigurations/systems for controlling the inventive valve 101, 101 amay be employed.

The foregoing description discloses only exemplary embodiments of theinvention. Modifications of the above disclosed apparatus and methodswhich fall within the scope of the invention will be readily apparent tothose of ordinary skill in the art. For instance, according to one ormore embodiments, pressure forces within the processing chamber Ptending to push the sealing portion 107 away from the processing chamberP may be opposed solely by bracing force generated by the bracingactuators 173. In other embodiments, the magnitude of the bracing forcemay be less than that required to oppose the pressure forces within theprocessing chamber P, and additional forces from other sources may beadded thereto to maintain a seal against the processing chamber opening102.

In at least one embodiment of the invention, the main body of thesealing portion 107 may be formed from a metal, such as aluminum or thelike. In such embodiments, the sealing portion 107 may include aresilient member 198 (FIG. 3E) that contacts the front plate 121 andprevents metal portions of the sealing portion 107 from contacting thefront wall 121 (e.g., so as to prevent particle generation frommetal-to-metal contact). The resilient member 198 may include, forexample, polyetheretherketone (PEEK) or another suitable material (e.g.,in the form of an o-ring or similar sealing member). Likewise, in atleast one embodiment, the main body of the bracing member 109 may beformed from a metal, such as aluminum or another suitable metal, andinclude a resilient member 199 (FIG. 3E) that contacts the back plate119 (to prevent particle generation from metal-to-metal contact). Theresilient member 199 may include, for example, polyetheretherketone(PEEK) or another suitable material (e.g., in the form of an o-ring orsimilar sealing member). It will be understood that as used herein, thesealing portion 107 may be said to contact the front plate 121 if itsresilient member 198 or any other portion of the sealing portion 107contacts the front plate 121. Likewise, the bracing member 109 may besaid to contact the rear plate 119 if its resilient member 199 or anyother portion of the bracing member 109 contacts the rear plate 119.

In at least one embodiment of the invention, the bellows 137 and/or theextensible wall portion 179 may be formed of stainless steel. Any othersimilar material may be employed.

Accordingly, while the present invention has been disclosed inconnection with exemplary embodiments thereof, it should be understoodthat other embodiments may fall within the spirit and scope of theinvention, as defined by the following claims.

1. A slit valve adapted to seal an opening comprising: a valve housinghaving: a first wall; a first opening formed in the first wall; a secondwall; and a second opening formed in the second wall; a closure memberhaving: a sealing portion adapted to contact the second wall and sealthe second opening; and a bracing member moveable relative to thesealing portion and adapted to contact the first wall; and at least oneactuating mechanism adapted to: move the sealing portion toward thesecond wall and into contact with the second wall; and move the bracingmember away from the sealing portion and into contact with the firstwall so as to brace the sealing portion against the second wall.
 2. Theslit valve of claim 1, wherein the at least one actuating mechanismincludes an actuator that comprises a portion of the closure member andis disposed between the bracing member and the sealing portion.
 3. Theslit valve of claim 1, wherein the sealing portion includes a resilientelement adapted to contact and seal against the second wall.
 4. The slitvalve of claim 1, wherein the bracing member includes a resilientelement adapted to contact the first wall.
 5. The slit valve of claim 1,wherein the bracing member is adapted to assume a retracted transverseposition within the sealing portion.
 6. The slit valve of claim 1,wherein the at least one actuating mechanism comprises a pneumaticactuator adapted to be selectably activated via positive pressure andvacuum pressure.
 7. The slit valve of claim 6, wherein the pneumaticactuator is adapted to employ positive pressure to move the bracingmember from a retracted transverse position against the sealing portionto a deployed transverse position against the first wall.
 8. The slitvalve of claim 6, wherein the pneumatic actuator is adapted to employvacuum pressure to move the bracing member from a deployed transverseposition against the first wall to a retracted transverse positionagainst the sealing member.
 9. The slit valve of claim 1, wherein the atleast one actuating mechanism includes a pneumatic actuator comprising apressure cell.
 10. The slit valve of claim 9, wherein a portion of thebracing member defines a boundary of the pressure cell.
 11. The slitvalve of claim 9, wherein a portion of the sealing portion defines aboundary of the pressure cell.
 12. The slit valve of claim 10, whereinthe at least one actuating mechanism further comprises a bellows, andwherein the bellows also defines a boundary of the pressure cell. 13.The slit valve of claim 12, wherein the bracing member is coupled to thesealing portion via the bellows.
 14. The slit valve of claim 13, whereinno coupling between the bracing member and the sealing portion existsexcept via the bellows.
 15. The slit valve of claim 12, wherein thebellows is oriented such that an expansion of the pressure cell producescontraction of the bellows.
 16. The slit valve of claim 12, wherein thebracing member comprises a plate, and wherein the plate also defines aboundary of the pressure cell.
 17. The slit valve of claim 16, whereinthe bracing member is adapted to assume a retracted transverse positionaway from the first wall such that the plate of the bracing member iswithin the sealing portion.
 18. The slit valve of claim 16, wherein thebracing member is adapted to assume a deployed transverse positionagainst the first wall such that the plate of the bracing member remainswithin the sealing portion.
 19. The slit valve of claim 1, wherein theat least one actuating mechanism includes a first actuating mechanismthat is external to the slit valve housing.
 20. The slit valve of claim19, wherein the first actuating mechanism comprises a pneumatic actuatoradapted to be activated via positive pressure.